A Thin Film Transistor-Liquid Crystal Display (TFT-LCD) has been widely applied to an electronic product such as a TV, a mobile phone, a display, etc, and occupied a dominant position in a tablet panel display field, since it is advantageous in that it can provide stable pictures and lively images, eliminate radicalizations, save space and power consumption, and the like.
In order to control a switching of the thin film transistor, in general, an apparatus for supplying gate driving voltages supplies a gate ON voltage VON to a gate driving integrated circuit, the gate ON voltage VON is generally between 18 V-30 V and its exact voltage value depends on a specific design of the thin film transistor. A Multi Level Gate (MLG) driving technique is usually utilized to reduce a picture flicker, that is, the gate ON voltage VON is processed by a Multi Level Gate driving integrated circuit (MLG IC). In particular, as shown in FIG. 1: at a specific time, a first preset voltage VGH would drop to a second preset voltage VGH′, wherein the second preset voltage VGH′ is lower than first preset voltage VGH but would not cause the thin film transistor to be turned off yet, so that a chamfered angle might appear in an output waveform of the gate driving integrated circuit, as illustrated in FIG. 2. There is a certain restoration time when the second preset voltage VGH′ is to be restored to the first preset voltage VGH due to a load, e.g., as a restoration time t shown in FIG. 3. A length of the restoration time t would affect a charging time of a liquid crystal display panel, and especially in a product for displaying pictures with a high frame rate, the length of the restoration time t is extremely important since a charging time of a driving thin film transistor is significant insufficient per se.
In conclusion, there is greatly desired an apparatus for supplying gate driving voltages and a method for supplying the gate driving voltages capable of shortening a time taken by the gate ON voltage to be restored to the first preset voltage VGH from the second preset voltage VGB′.